Researchers from the Harvard Medical School created a preventive vaccine that is expected to robust immune responses against HIV
According to the World Health Organization, 36.7 million people were infected with HIV at the end of 2016. A research led by Professor Dan Barouch of Medicine at Harvard Medical School created an experimental HIV-1 vaccine that generated comparable and robust immune responses against HIV in healthy adults and rhesus monkeys. The research team involved 400 healthy adults and 2,600 women at risk for acquiring HIV, for a clinical trial. The previous HIV-1 vaccine candidates were limited to specific regions of the world. However, the mosaic Ad26 prime, Ad26 plus gp140 boost HIV vaccine candidate induced robust immune responses in humans and monkeys with comparable magnitude and durability. The vaccine also proved efficient in providing 67% protection against viral challenge in monkeys. Professor Dan Barouch stated that the vaccine’s ability to induce HIV-specific immune responses does not necessarily indicate that it will protect humans from HIV infection as another results from phase 2b efficacy trial called HVTN705 are awaited. The research was published in the journal The Lancet on July 6, 2018.
The team evaluated the leading mosaic adenovirus serotype 26 (Ad26)-based HIV-1 vaccine candidates in parallel clinical and pre-clinical studies. To stimulate an initial immune response, each volunteer received an intramuscular injection of Ad26.Mos.HIV at the start of the study and again 12 weeks later. The vaccine containing ‘mosaic’ HIV Env/Gag/Pol antigens was created from many HIV strains, delivered using a non- replicating common-cold virus (Ad26). The volunteers were given two additional vaccinations at week 24 and 48 using various combinations of Ad26.Mos.HIV. It was observed that all vaccine regimens tested generated anti-HIV immune responses in healthy volunteers. However, very few participants suffered from abdominal pain and diarrhea or dizziness and back pain. The researches stated that there are several limitations to the study as there is no definitive immunological measurement that is known to predict protection against HIV-1 in humans.